07. Molecular Biology & Recombinant DNA Technology [DEFINITIONS] Flashcards
Architecture of Chromosomes
The architecture of chromosomes is the way the DNA molecules are arranged in the nucleoid or nuclear region of the cytoplasm of the prokaryotic cells in the nucleus of eukaryotic cells.
Chromosome
DNA of both prokaryotes and eukaryotes are called chromosomes
Chromatin
Eukaryotic chromosomes are associated with a large number of proteins called histones that helps to organize the DNA inside the nucleus. This DNA-protein complex is known as chromatin.
Heterochromatin
Euchromatin
Lightly packed chromatin is euchromatin.
Tightly packed chromatin is called heterochromatin.
DNA Replication
DNA replication is the process which copies a double stranded DNA molecule to produce two identical copies.
Gene
A gene is the fundamental physical and functional unit of heredity.
Operon
A operon is a group of genes that functions as a single transcription unit comprised of a control region (an operation, a promoter) and structural genes that are transcribed into one mRNA coding for several peptides.
Gene Expression
A gene expression is the process by which the information stored in a gene is used to make a functional gene product.
Genetic Code
A combination of nucleotides that would be needed to code for one amino acid containing four letters is a genetic code.
Transcription
Copying a sequence of DNA into mRNA
Initiation of transcription
It is a process initiated at a specific site called the promoter where the one strand of double stranded DNA acts as template.
Elongation of transcription
This is the process where RNA polymerase starts adding complementary ribonucleotides against the template DNA by RNA polymerase in the 5’ to 3’ direction until reaching the production termination site.
Termination of transcription
Translation
Converting the information in mRNA to a sequence of amino acids
Promotor
The process of transcription is initiated at a specific site called promotor
Transcription Termination Site
RNA polymerase enzymes can start adding complementary ribonucleotides against the template DNA. RNA polymerase continues to add nucleotides in 5’ to 3’ direction until it reaches the transcription termination site.
Transfer RNAs (tRNA)
Ribosomes read the message written as a sequence of triplet codons in an mRNA and translate it into a sequence of amino acids in a polypeptide with the assistance of transfer RNAs (tRNA)
Initiation of Translation
The first step in initiation is binding of small subunit of ribosome to mRNA and to the initiator tRNA which carries methionine as the first amino acid. Then, the two subunits of the ribosome combine to form the functional ribosome.
Elongation of translation
This is a stage where amino acids are added to the C- terminus of the growing polypeptide chain by peptide bonds, one after the other governed by the triplet codons.
Termination of translation
When the mRNA moves, it finally aligns one of the stop codons: UAG, UAA, or UGA with A site
Polyribosomes / Polysomes
mRNAs translated actively are associated with multiple ribosomes attached to a string to mRNA, forming polyribosomes or Polysomes
Polyribosomes / Polysomes
mRNAs translated actively are associated with multiple ribosomes attached to a string to mRNA, forming polyribosomes or Polysomes
Mutation
An alternation of the nucleotide sequence of the genome of an organism is a mutation
Isolation of DNA
Gene technology beings with the isolation of the target DNA sequence from the total genome of the donor cells.
DNA Probe
A DNA probe is a fragment of single stranded labelled DNA used to detect the presence of complementary nucleic acid sequences by hybridization.
Labelling
Labelling is a modification of the DNA strand in such a way that it gives a signal which enables the detection of that DNA strand.
Southern Blotting
This is a process where the denatured bands on the gel need to be transferred to a nitrocellulose or nylon filter membrane
Recombinant DNA Molecules
DNA molecules made by laboratory methods of genetic recombination which brings together DNA from different sources, creating sequences that are not found naturally.
Recombinant Vector
When the vector is carrying the foreign DNA, it is a recombinant vector.
Transformation
The direct uptake of exogenous DNA from the surroundings of a host through its cell membrane and incorporation, resulting in a genetic alteration
DNA Libraries
DNA libraries are a collection of microbial cultures each propagating a different fragments of a total genomic DNA which are cloned in a population of identical vectors.
Restriction Maps
A restriction map is a diagram showing the position of each restriction site with respect to each other and the distant between these sites.
DNA Sequencing
DNA sequencing is a process to determine the precise order of these bases in a DNA molecule
DNA Fingerprinting
The unique set of genetic markers of an individual makes its DNA fingerprint or genetic profile.
Polymerase Chain Reaction - PCR
PCR is used to copy sequences of DNA in vitro, mimicking the DNA replication using the raw materials such as deoxyribonucleotide triphosphate (dNTPs) including four deoxyribonucleotides (dATP, dGTP, dTTP, and dCTP)
Genetically Modified Organism (GMO)
The hose with the extra trait introduced by genetic engineering techniques is called a genetically modified organism (GMO)
Cartagena Protocol
This is an international agreement signed on may 15th of 2000 in Montreal, Canada to protect biological diversity from potential risks caused by genetically modified organisms or living modified organisms LMOs) created as a result of modern biotechnology.
